1. Field
Implementations of the present invention generally relate to repairing and lowering the dielectric constant of low-k dielectric films used in semiconductor fabrication.
2. Description of the Related Art
The dielectric constant (k) of dielectric films in semiconductor fabrication is continually decreasing as device scaling continues. Minimizing integration damage on low dielectric constant (low-k) films is important to be able to continue decreasing feature sizes. However, as feature sizes shrink, improvement in the resistive capacitance and reliability of dielectric films becomes a serious challenge.
Porous low-k dielectric films including for example, carbon-doped oxides (CDO), experience damage to their bonding structures when exposed to integration steps such as, but not limited to, chemical mechanical polishing (CMP) or planarization, etching, ashing, and cleaning. In particular, Si—H and Si—OH bonding increases in concentration after one or more of these integration steps. This increase in Si—H and Si—OH may lead to an increase in k-value. Present repair techniques involve liquid phase silylation or use of supercritical CO2. However, such techniques have not proven effective for repairing sidewall damage of recessed features in the films.
Thus, a method for repairing the dielectric films to lower the k-value is necessary to improve efficiency and allow for smaller device sizes.